West Nile virus found in Acton

Tuesday

The Massachusetts Department of Public Health announced Aug. 16 that two mosquitoes collected in Acton had tested positive for West Nile virus.

Two human cases of West Nile virus in Middlesex County have also been reported, the DPH confirmed.

Acton is one of many towns in the state where recent hot and humid weather, combined with frequent rainfall, have provided "perfect conditions for mosquito species carrying West Nile Virus to breed," according to Public Health Commissioner Monica Bharel.

The trend across the state has prompted the Massachusetts Department of Public Health to elevate the risk from low to moderate statewide.

According to the Center for Disease Control, most people infected with West Nile virus have no symptoms from the infection, but about one in five people who are infected develop a fever and other symptoms. In rare cases, people can develop a more serious and sometimes fatal infection.

State officials said people over the age of 50 were at a greater risk of developing severe symptoms.

No cases of West Nile virus have been reported in humans or creatures other than mosquitoes, according to the state’s Executive Office of Health and Human Services. Since the disease is most commonly transmitted to humans from mosquito bites, public health officials are asking residents to be especially vigilant about avoiding mosquitoes.

"I strongly encourage everyone to keep using insect repellent and to be especially aware of mosquito activity at dusk and dawn when the risk of being bitten by mosquitoes is greatest. Move indoors if you are getting bitten," said Bharel.

Concord town officials released a list of steps residents can take to protect themselves and their loved ones from West Nile virus, as well.

To prevent bites, the list suggests using a repellent with DEET, permethrin, picaridin, IR3535 or oil of lemon eucalyptus. They also recommend using clothing to create a physical barrier.

“Although it may be difficult to do when it’s hot, wearing long sleeves, long pants and socks when outdoors will help keep mosquitoes away from your skin,” according to the town’s instructions.

Town officials also recommend residents “mosquito-proof” their homes by draining any standing water where mosquitoes could lay eggs and by installing or repairing window screens to keep the insects out while windows are open.

Concord has hired East Middlesex Mosquito Control Project to assist with mosquito control through adult mosquito surveillance and larval mosquito control with two biological agents called Vectolex WSP and Bti, according to the town’s website. The town does not use any aerial spraying as a means of mosquito control.

In an information packet distributed by the Massachusetts Department of Public Health, state officials remind residents that while caution is recommended, the risk of contracting West Nile virus is still low.

“Only a small proportion of mosquitoes are infected at any given time. Thus, being bitten by a mosquito does not mean a person will become sick,” according to the booklet.

Michael P. Norton/State House New Service contributed to the reporting in this article.